We explore differences in firms’ attitudes towards corporate social responsibility (CSR). Using a unique dataset covering 8,857 French firms, collected by the National Institute of Statistics and Economic Studies (INSEE), we identify firms conducting conscious CSR and others with effective but unaware CSR activities. We then construct three CSR pillar scores for each firm, using Mokken scale analysis, a form of non-parametric item response analysis. The CSR scores, along with responses to specific questions, allow us to characterize firms that implement conscious or unaware CSR. We then estimate simple probit and count data models to show that a significant share of firms are in fact actually engaged in unaware CSR, with no monotonic size effect. Cooperation with external actors such as NGOs mitigates the effect of firm size on the likelihood of conducting unaware CSR, while the effect of NGO campaigns against large firms is mainly to increase the environmental score of small firms in the same industry.